The present application pertains generally to methods and apparatus for tipping smoking articles, and pertains more especially to such methods and apparatus for tipping oval smoking articles.
In the manufacture of cigarettes, it is conventional to make a continuous tobacco rod (a paper tube filled with shredded tobacco or tobacco substitute) and to cut the continuous rod to the length of individual cigarettes. A continuous rod of filter material is extruded and cut into lengths. The resulting filter plugs are collected in trays and placed in the hopper of a tipping machine, which cuts the filter plugs to twice the length of a single filter, joins each double-length filter plug to two filterless cigarettes and severs the resulting assembly to form two complete cigarettes.
The filter plugs are gravity-fed from the hopper into flutes or grooves in the periphery of a rotating drum. The filter plugs are held in place in the flutes by means of vacuum suction exerted from the drum interior. The filter plugs can be passed from one such drum to another by proper timing of the rotations of the two drums, and by simultaneously deactivating the suction applied to a particular groove of the first drum as that groove comes face-to-face with a groove of the second drum. This permits a filter plug in the first flute to be pulled over into the opposing flute of the second drum by the suction applied to the latter. The filter plugs passed in this manner from one drum to another eventually are transferred to the flutes of a feed drum. In each flute two previously-deposited cigarette rods flank the filter plug end-to-end.
A web of cork or other tipping material is drawn from a roll thereof and has glue applied to one side. The web is cut off in lengths by cork knives, and one edge of each length is applied to a filter-plug-and-cigarette assembly in such a manner as to extend over the entire length of the filter plug and to overlie a small portion of each cigarette rod, the adhesive on the tipping material sticking to the plug and the rod.
The resulting double cigarette assembly is transferred to a rolling drum, beside which is a metallic rolling block. Each cigarette assembly is rolled along the rolling block while being moved by the drum. The rolling action wraps the tipping material around the cigarette assembly, to which it adheres as a result of the glue. Suitable heating elements in the rolling block commonly are used to cure the adhesive rapidly.
The double cigarette assembly is then transferred to a cutter drum, which moves it past a disc knife that severs the assembly into two complete cigarettes. The cigarettes are then inspected and moved to a discharge point, from which they are taken to another machine for packing.
The conventional tipping machine described above is designed to handle cigarettes of circular cross section. It would be desirable to be able to adapt a standard cigarette tipping machine for use in the rapid, economical large-scale manufacture of cigarettes having an oval cross section, which have hitherto largely been a luxury product requiring special equipment for virtually every step of their manufacture. Two particular problems arise in making such an adaptation. First, it is difficult to transfer oval filter plugs from the hopper to a drum of the conventional type in such a manner that every flute will contain a filter plug and so that each filter plug will have the same predetermined orientation about its longitudinal axis (hereinafter, "angular orientation"). Second, it has been found to be impossible, as a practical matter, to wrap tipping material around a cigarette assembly having an oval cross section, using standard tipping machine equipment.
Related copending application Ser. No. 584,366 filed Feb. 28, 1984, which is a continuation-in-part of related copending application Ser. No. 480,807, filed Mar. 31, 1983, both, entitled "Method and Apparatus for Tipping Oval Smoking Articles," assigned in common herewith, and the entire contents and disclosure of which are incorporated herein by reference, are directed to a solution of the second problem. The present invention is a solution of the first problem.
It is therefore the principal object of the invention to provide a method and apparatus for giving a filter plug of oval cross section a predetermined angular orientation.
Another object of the invention is to provide such a method and apparatus by means of which it is possible to take an oval filter plug from a hopper containing a large number of such articles and to give it the desired angular orientation.
Yet another object of the invention is to achieve the foregoing objects in a manner which permits the ready and easy adaptation of existing tipping machines to the production of oval cigarettes.